1. Field of the Invention
The present invention relates generally to a disk clamping device for holding an optical disk firmly and, more particularly, to a disk clamping device which is capable of preventing the slipping or eccentricity of an optical disk when the optical disk rotates at high speeds.
2. Description of the Related Art
Generally, in an optical disk device for recording and reproducing data on an optical disk such as a compact disk (CD), a digital versatile disk (DVD) or a blu-ray disk (BD), a portable device occupies an important part in a related industrial field and has been developed to record/reproduce data at high density and high speeds as the amounts of data which are used increases, and to increase the convenience of transportation in order to improve on the degree of time and spatial freedom for demand for data.
One of the important features of the optical disk device is to prevent the slipping of the optical disk when it rotates at high speeds, and to prevent the eccentricity of the optical disk when the optical disk is mounted.
One example of a conventional clamping device for attaching and detaching an optical disk is schematically shown in FIG. 9.
As shown in FIG. 9, the conventional clamping device 10 includes a housing 11, a clamping magnet 16 and a claw part 15.
The housing 11 is used to seat an optical disk (not shown), and is seated on a rotor casing 21 of a spindle motor in such a way as to be secured to a rotating shaft 22. Here, a shaft insert hole 12 is formed in the central portion of the housing 11 so that the rotating shaft 22 is inserted into the shaft insert hole 12, and a seat 13 on which the optical disk is to be seated extends perpendicular to the rotating shaft 22. Further, the housing 11 is constructed so that a hub 14 which is to be inserted into the central hole of the optical disk protrudes from the center of the seat 13. The claw part 15 is integrally provided on the hub 14 to guide the insertion of the optical disk.
The clamping magnet 16 generates attractive force with respect to a chucking part (not shown) which presses the upper portion of the optical disk seated on the seat 13 of the housing 11 to hold the optical disk. The clamping magnet 16 is provided on the upper portion of the hub 14 of the housing 11 in such a way as to be adjacent to the rotating shaft 22.
The claw part 15 functions to guide the optical disk which is to be seated on the housing 11 and is integrally provided on the hub 14 of the housing 11. The claw part 15 is formed in the shape of a claw in such a way as to be elastically deformed towards the inside portion of the housing 11, that is, towards the rotating shaft 22. That is, the claw part 15 has on its upper portion an inclined surface 15a to guide the optical disk.
In the case of mounting the optical disk to the clamping device 10 constructed as described above, the hub 14 of the housing 11 is inserted into the central hole of the optical disk, and the optical disk is seated on the seat 13 of the housing 11. At this time, in order to guide the insertion of the optical disk, the inclined surface 15a of the claw part 15 is in contact with the central hole of the optical disk.
That is, the claw part 15 guides the optical disk to be seated on the housing 11 such that the eccentricity of the optical disk is prevented.
However, in the conventional clamping device 10, the claw part 15 is designed to be elastically deformed towards the inside portion of the housing 11. Thus, when the housing 11 rotates at high speeds, the optical disk elastically deforms the claw part 15, so that the optical disk slips, thus causing the eccentricity of the optical disk.
That is, in the case of using an optical recording medium such as a DVD which requires high-speed rotation and low eccentricity, the eccentricity or slipping of the optical recording medium must be prevented.